This invention relates to the teaching and musical arts. Specifically the present invention is a training device for students of stringed instruments. Improper positioning of the wrist while performing Vibrato musical passages is a common problem with such students. Unfortunately the problem is one which does not easily manifest itself to the student until the later stages of training. The longer defective wrist positioning is permitted to persist the harder it is to extinguish. In the later stages of training, faulty wrist positioning impedes, or in some cases makes impossible, certain techniques which must be mastered to achieve higher levels of virtuosity. The advantage of the present invention is that it provides immediate feedback to the student as soon any vibrato techniques are attempted with improper wrist positioning. Provision of this feedback early in a student's education prevents extensive unlearning of wrist position which occurs in some students.